Pediatric Neuromuscular Ultrasound to Augment the Diagnostic Capabilities for Scapular Winging.

Background Subjects with a winged scapula (WS) can cause musculoskeletal disorders of the shoulder due to uncontrolled movement of the scapula during shoulder flexion. A WS results in abnormal positioning of the scapula, leading to shoulder dysfunction. Objectives This study is to compare shoulder flexion strength, electromyography (EMG) activity of the periscapular muscles, and scapular winging during shoulder flexion in subjects with and without a WS. Methods Twelve with and thirteen without a WS participated in this study. To compare shoulder flexion strength, muscle activity, and scapular winging between the two groups, maximal flexion was measured using a tensiometer during shoulder flexion. Concurrently, surface EMG was used to measure the activities of the upper trapezius (UT), anterior deltoid (AD), serratus anterior (SA), and lower trapezius (LT) muscles, and a scapulometer was used to measure scapular winging during shoulder flexion. The independent t-test was used to compare shoulder flexion strength, muscle activity, and scapular winging between the two groups. Results There was no significant difference in shoulder flexion strength between the two groups (p = 0.172). The activities of the SA and UT muscles decreased significantly in subjects with a WS compared to subjects without a WS (p = 0.001 vs p = 0.023). In addition, scapular winging was significantly greater in subjects with a WS compared to those without a WS (p = 0.001). Conclusions These findings muscle activities of the SA and UT in subjects with WS is associated with upward rotation of the scapula and scapular winging rather than shoulder flexion strength. This may be supporting evidence for exercises reflecting the degree of activity of the muscles around the shoulders rather than focusing on the shoulder flexor during physical therapy related to shoulder flexion in a clinical setting.

To examine the differences between men with and without scapular winging in the electromyographic (EMG) amplitude and activity ratio between the pectoralis major (PM) and serratus anterior (SA) during 3 push-up plus exercises: (a) the standard push-up plus (SPP), (b) the knee push-up plus (KPP), and (c) the wall push-up plus (WPP), and to determine which exercise induced the lowest PM/SA ratio in each group. Twenty-eight men participated in this study (13 scapular winging group: age, 21.8 ± 2.1 years; 15 control group: age, 23.3 ± 2.0 years). Surface EMG of the PM, SA, and activity ratio between the PM and SA were collected during 3 push-up plus exercises, and the EMG data were expressed as a percentage of the reference voluntary contraction (%RVC). The normalized PM activity for subjects in the scapular winging group was significantly greater than that in the control group (79.16 ± 6.65 %RVC vs. 39.66 ± 6.19 %RVC, p ≤ 0.05). The normalized SA activity was significantly lower in the scapular winging group compared with the control group (39.80 ± 4.09 %RVC vs. 56.28 ± 3.81 %RVC, p ≤ 0.05) and was significantly decreased in the following order: SPP > KPP > WPP; 77.09 ± 5.12 %RVC > 39.48 ± 3.38 %RVC > 27.55 ± 3.07 %RVC, p < 0.016). The PM/SA EMG ratio was significantly greater in the scapular winging group compared with that in the control group across all exercises and was significantly lower during SPP than that during KPP and WPP in both groups (1.13 ± 0.58 vs. 0.53 ± 0.25 for SPP, 3.50 ± 2.07 vs. 0.92 ± 0.63 for KPP, 4.04 ± 3.13 vs. 1.19 ± 0.66 for WPP, p < 0.016). Greater PM activity was found in the scapular winging group, and the SPP is an optimal exercise for subjects with scapular winging, where maximum SA activation with minimal PM activation is desired.

Effect of isometric horizontal abduction on pectoralis major and serratus anterior EMG activity during three exercises in subjects with scapular winging

The objectives of this study were to electromyographically (EMG) describe and analyze factors associated with long thoracic nerve injuries in breast cancer patients after axillary lymph node dissection. This was a prospective longitudinal observational study. Two hundred sixty-four women with primary invasive breast cancer were included between 2008 and 2011. All of them were treated by axillary lymph node dissection. Patients were evaluated at 1, 6, and 12 months following surgery. The presence of winged scapula was systematically tested at each follow-up and an EMG performed whenever it was observed. Affected and unaffected groups were compared for demographic, tumour, and treatment variables. Student t test, Mann-Whitney U test, chi-squared or Fisher test were computed as appropriate. Among the 36 (13.6%) winged scapula observed, the EMG confirmed long thoracic nerve injury in 30 (11.3%) of them, 27 were partial axonotmesis and three were severe axonotmesis. At 12 months, the EMG showed that injury persisted in six (2.27%) patients. Patients with long thoracic nerve injury had a lower body mass index than unaffected patients (26.2 vs. 28.2, p = 0.045). Age, tumour stage, type of breast surgery, nodes excised, surgical complications, previous chemotherapy and previous hormonotherapy were not factors associated with winged scapula. A lower body mass index was the only factor associated to long thoracic nerve injury. In most of the patients, the EMG showed partial axonotmesis. At 12 months, 2.27% of studied patients remained with an unsolved long thoracic nerve injury.

Scapular winging and tipping are types of abnormal scapular kinematics, which is caused by not only the entrapment of peripheral nerve, but also imbalance of the scapulothoracic musculatures. The purpose of this study was to investigate the presence of muscular imbalance in the middle and lower parts of the serratus anterior and upper trapezius in people with scapular winging and tipping. Twenty male participants (age, 23.0 ± 1.92 y) were placed into symptomatic group (n = 10) and control group (n = 10). Participants completed two individual trials of a push-up plus, and a diagonal shoulder elevation, while electromyography (EMG) recorded muscle activity of the low and middle serratus anterior and upper trapezius. The root mean squared EMG values for three muscles were normalized using maximum voluntary isometric contractions (%MVIC). The value was calculated using modified isolation equation for comparing activation of middle and lower serratus anterior (%isolation). During a diagonal shoulder elevation, the % maximal voluntary isometric contraction (%MVIC) data showed that the symptomatic participants had significantly greater activation of the middle serratus anterior compared to the control group (P = 0.01). During a diagonal shoulder elevation, the symptomatic participants had not only significantly increased %isolation of the middle serratus anterior, but also significantly decreased for the lower serratus anterior compare with the control group (p = 0.00). Present result indicated that different muscle activation between middle and lower serratus anterior could represent in group with scapular dyskinesis, and need for selective activation of the lower serratus anterior in patients with scapular winging and tipping.

1 - Approach to Nerve Conduction Studies, Electromyography, and Neuromuscular Ultrasound

Long thoracic nerve release for scapular winging: Clinical study of a continuous series of eight patients

Pneumothorax is a well-known and feared complication of needle electromyography (EMG) of the diaphragm. However, pitfalls that may lead to, precautions to avoid and approach after occurrence of pneumothorax have been only briefly described in the literature [1]. Therefore, I report my first patient with idiopathic bilateral phrenic neuropathy and pneumothorax caused by needle EMG of the diaphragm. A 72-year-old retired man (body mass index 30 kg/m) treated for hypertension, but with no other disease (e.g., chronic obstructive pulmonary disease (COPD) or diabetes), underwent lumbar spinal stenosis surgery. On the fifth postoperative day, he suddenly noted severe pain at the tip of the right shoulder, difficulty in moving the arm, and sensory loss in the lateral aspect of the superior third of the arm. He noted that he was not able to breathe while recumbent. X-ray and CT scan of his chest demonstrated bilateral elevation of the diaphragm with basal atelectases. Ultrasound examination also found poor respiratory movement of the diaphragm. Pulmonary function tests showed restrictive defect with hypercapnic respiratory failure. On neurological examination in the fifth week of disease inability to lay supine, paradoxical respiratory abdominal movements, pronounced right-sided winging of the scapula, and slightly diminished sensation over the lateral aspect of the superior third of the right arm were found. On nerve conduction studies [2], no reproducible phrenic nerve compound motor action potentials were found bilaterally. Needle electrode was inserted bilaterally in the medial recess of the sixth intercostal space for EMG of the diaphragm (Fig. 1), and towards the eighth rib in the right middle axillary line for EMG of the serratus anterior muscle; spontaneous denervation activity was found in all three muscles. Furthermore, no characteristic motor unit potential (MUP) firing pattern during inspiration was found in the diaphragm, and severe interference pattern reduction in the right serratus anterior muscle. Nerve conduction studies and EMG of the additional nine, mainly C3–6 segment muscles, were normal. On a follow-up visit 3 months later, the patient reported that he had suffered a right-sided pneumothorax following the electrodiagnostic examination. He denied any subjective difference in perception of the diaphragm needle EMG on the left and right side. In the first hour after electrodiagnostic studies, while waiting outside of our department for transport home, he noted only a slight increase in breathing difficulty. However, his breathing became increasingly difficult during his 2-h journey home. On arrival home he felt like he had ‘‘a stone in his right chest’’. He immediately contacted the local electrodiagnostic physician, who directed him to the local hospital. Chest X-ray demonstrated a large right-sided pneumothorax. A pleural drain was inserted, and breathing returned to the pre-complication state in 1 h. Patient received methylprednisolone 500 mg i.v. on five consecutive days. For treatment of his respiratory failure over-night non-invasive ventilation was started and still continues several years later. Sudden severe shoulder pain, followed by hypesthesia over the lateral aspect of the arm, with scapular winging, probably triggered by the surgical procedure in an anatomically distant region 5 days previously, are all typical of neuralgic amyotrophy [3]. However, according to clinical, electrodiagnostic and imaging studies, the presumed autoimmune process also caused bilateral phrenic S. Podnar (&) Division of Neurology, Institute of Clinical Neurophysiology, University Medical Center Ljubljana, 1525 Ljubljana, Slovenia e-mail: simon.podnar@kclj.si

Brachial plexus upper trunk injury is associated with winged scapula owing to the close anatomical course of the long thoracic nerve and upper trunk. Needle electromyography is a common diagnostic test for this injury; however, it does not detect injury in most patients with upper trunk damage. The pressure-specified sensory device may be an alternative to needle electromyography. Thirty patients with winged scapula and upper trunk injury were evaluated with needle electromyography (EMG) and pressure-specified sensory device (PSSD) tests. EMG testing of the biceps muscle was compared with PSSD testing of the dorsal hand skin (C6 damage), and EMG testing of the deltoid and spinati muscles was compared with PSSD testing of the deltoid skin (C5 damage). PSSD pressure values were significantly higher on the affected arm. On the basis of published and calculated threshold values the PSSD was found to be significantly more sensitive than EMG. The PSSD tests consistently identified injuries that were not detected by needle EMG tests. These findings provide strong evidence that the PSSD is more effective than needle EMG in the detection of brachial plexus upper trunk injury.

The diagnosis and evaluation of neuromuscular disorders traditionally involves electrodiagnostic (EDx) testing, including nerve conduction studies (NCSs) and electromyography (EMG). These tools can cause pain and discomfort, an important consideration when performed on children. Neuromuscular ultrasound is noninvasive, cost-effective, and increasingly utilized for the detection of neuromuscular pathology. Studies investigating the performance and clinical implementation of ultrasound have primarily been performed in adult populations. Ultrasound in children has the potential to guide EDx testing and ultimately improve diagnostic efficiency and accuracy. This review aims to describe key features of neuromuscular ultrasound in the pediatric population based on the available studies, including our own institutional experience.

Effect of Abdominal Drawing-in Maneuver on the Scapular Stabilizer Muscle Activity During Push-up Plus Exercise in Subjects With Scapular Winging

Limb-girdle muscular dystrophy (LGMD) is a genetically and clinically heterogeneous group of neuromuscular disorders characterized by progressive proximal muscle weakness and varying patterns of scapular winging. Accurate subtype identification is often hindered by diagnostic complexities and limited access to advanced diagnostic tools, particularly in resource-constrained settings. We present the case of a 38-year-old male with a 10-year history of progressive upper limb weakness, scapular winging, and persistent fatigue. Electromyography (EMG) revealed a myopathic pattern, supporting the clinical suspicion of LGMD. Muscle biopsy and genetic testing were not performed due to patient unwillingness and financial limitations. A multidisciplinary management approach comprising low-dose corticosteroids, physiotherapy, and nutritional support led to symptomatic improvement and enhanced functional capabilities. This case underscores the diagnostic challenges posed by the absence of advanced genetic and histopathological investigations and highlights the importance of accessible, patient-centered care. Scapular winging and proximal weakness were pivotal diagnostic features in this case, reflecting the hallmark manifestations of LGMD. The observed improvement with physiotherapy and corticosteroids demonstrates the value of a tailored management strategy in mitigating the impact of this progressive condition. This case emphasizes the need for broader access to diagnostic innovations and advanced therapeutic options to optimize care for patients with rare neuromuscular disorders.

Coccidioidomycosis, a fungal infection caused by inhaling spores of Coccidioides immitis/posadasii, is endemic to the southwestern states of the United States, Northern Mexico and some parts of Central and South America. It is primarily a pulmonary infection with less than 0.5% of symptomatic cases showing dissemination. Skin, lymph nodes and bone are the commonest sites. Neurological involvement is rare and commonly presents as strokes, abscesses or meningoencephalitis. We present the case of a previously healthy 23-year-old African American male, presented with a four-month history of progressive right upper extremity weakness that initially started with right shoulder pain followed by worsening weakness and loss of muscle mass. Electromyography (EMG) demonstrated right brachial plexopathy with moderate-to-severe active denervation changes. MRI cervical spine revealed a 9-cm contrast enhancing extradural mass extending through the neural foramen from C4-T1 roots and forming a 4-cm right apical lung mass subsequently seen on MRI of the brachial plexus. All trunks, divisions and cords were thickened, hyperintense and showed contrast enhancement on MRI. Neuromuscular ultrasound (NUS) demonstrated enlargement of peripheral nerves. Differentials prior to biopsy of the mass ranged from neurofibromas to pancoast lung tumors. Coccidioidomycosis did not figure on the initial list of differentials. Patient underwent subsequent biopsy of the extradural and lung masses that showed coccidiodes. Serum coccidioides antibody titers were elevated. The patient was treated with high-dose intravenous fluconazole and aggressive mass debridement. His weakness improved on four months follow-up evaluation with significant resolution of EMG abnormalities and decreased swelling on NUS.

108. Electromyography integrated with neuromuscular ultrasound evaluation in pediatric age: Description of two clinical cases

Paediatric electromyography (EMG) is an invaluable diagnostic test for the investigation of neuromuscular disease, but its use is inconsistent between and within different countries. One perception is that the procedure is painful; however, in comparison with common investigations performed routinely in children, EMG is better tolerated. While some developments, such as those within clinical genetics, would appear to mark its demise, paradoxically the more genetic abnormalities that are discovered in conditions such as hereditary neuropathy, the more precise a delineation of the phenotype is required. EMG has particular strengths in the diagnosis of neuropathies, motor neuronopathy and neuromuscular transmission disorders such as myasthenia. Also, it can supplement the investigation of myopathies. Areas of development include the diagnosis of myasthenia, delineation of bulbar palsy as a cause of dysphagia, more accurate and earlier prediction of prognosis in neonatal brachial palsy and investigation of channelopathies. It is a valuable diagnostic tool in developed countries and those with limited resources.